About Us

The Person Behind ONISIS: Konstantinos Kormentzas

Over 10 years in C-level roles — now sitting on your side of the table.

Former Chief Risk Officer, Internal Audit Lead, and COO in banking. Active entrepreneur.

A track record brought in full to every client engagement.

Konstantinos Kormentzas, founder and principal consultant of ONISIS

WHY I FOUNDED ONISIS

WHY I FOUNDED ONISIS

“Under the pressure of daily execution, even textbook realities become invisible.”

Behind every analysis and financial strategy at ONISIS stands Konstantinos Kormentzas. Having spent over 20 years in banking, he understands in depth how businesses are evaluated financially and how to negotiate with credit institutions from strength.

The impetus for founding ONISIS grew out of the first business Konstantinos operated after leaving the corporate sector. There, he experienced firsthand the financial mistakes that textbooks warn against.

He had technical expertise. What he lacked was an independent partner who could review the numbers objectively and warn him in time: 'Careful, we are going the wrong way.' The people around him stayed silent. That experience defined ONISIS: standing beside management with honesty, practical answers, and zero corporate theater.

PERSONAL MESSAGE

A letter from the founder to the business owner

I know what you might be thinking: 'Another consultancy asking for my trust.'

I understand completely. That is why I will tell you something you rarely hear from a consultant:

I am not here to promise magical solutions or guarantee outcomes that do not depend on us. That would be dishonest, and neither of us wants our relationship to start that way.

What I can tell you with complete sincerity is this: I have sat in your exact seat. I understand the weight of that chair, the nonstop operational demands, and the quiet anxieties of leadership. I know what it feels like to carry the entire business on your shoulders without an independent sounding board beside you who speaks straight, without hesitation or secondary motives.

That is why I do not ask for your trust on day one. I only ask for an honest, direct conversation.

In that discussion, based on how we examine your numbers and challenges, you will judge for yourself whether working together makes sense.

Trust is never built with promises. It is built by the way we listen, the way we analyze, and the way we speak straight.

Konstantinos Kormentzas

Founder & Principal Consultant, ONISIS Consulting

Your next decision starts with an honest conversation.

Your first discussion is held directly with Konstantinos, not a sales representative. You will hear an honest assessment of what can and cannot be achieved. And if your business is already on a healthy trajectory, we will tell you straight, free of charge.

The Person Behind ONISIS: Konstantinos Kormentzas | ONISIS